WO2011083510A1

WO2011083510A1 - Refrigeration cycling device and expander installed in same

Info

Publication number: WO2011083510A1
Application number: PCT/JP2010/000060
Authority: WO
Inventors: 角田昌之; 石園文彦; 永田英彰; 下地美保子; 関屋慎; 幸田利秀; 加賀邦彦
Original assignee: 三菱電機株式会社
Priority date: 2010-01-07
Filing date: 2010-01-07
Publication date: 2011-07-14
Also published as: JPWO2011083510A1; EP2522932A1

Abstract

Provided are a refrigeration cycling device that is capable of flow rate matching without pre-expansion or by-passing an expansion mechanism, and an expander installed in such a refrigeration cycling device. A refrigeration cycling device (100) has an expander (1) that is provided with a swing scroll having a base plate with spirals on both sides thereof. Formed in the base plate is a high pressure guiding hole (52e) for guiding the pressure of a refrigerant introduced into an expansion mechanism (2) towards a sub compression mechanism (3).

Description

Refrigeration cycle apparatus and expander mounted thereon

The present invention relates to a refrigeration cycle apparatus that recovers expansion power generated during expansion of a refrigerant and uses the expansion power for compression of the refrigerant, and an expander mounted thereon.

In a refrigeration cycle used for refrigeration and air conditioning, when a refrigerant is decompressed by a positive displacement fluid machine and the expansion power is recovered, and the recovered power is used for the refrigerant compression process performed by the positive displacement fluid machine The so-called “constant constant density ratio” matching of the volume flow rate of the refrigerant must be considered. In such a displacement type fluid machine, since the ratio of the refrigerant suction volume of the expansion mechanism and the refrigerant suction volume of the compression mechanism linked by receiving the recovery power from the expansion mechanism is fixed, the refrigerant passing through both of them is fixed. If the flow rates of the two are the same, the ratio of the refrigerant specific volume at the inlets of both mechanisms needs to match the ratio of the suction volume.

The expansion machine is designed on the condition that the ratio of the refrigerant specific volume of the expansion / compression inlet and the suction volume ratio are the same, and in order to match the deviation from the design point with the change in conditions during actual operation, In the case of refrigerant specific volume / compression inlet refrigerant specific volume)> (expansion suction volume / compression suction volume), the expansion mechanism is bypassed by a predetermined flow rate, and (expansion inlet refrigerant specific volume / compression inlet refrigerant specific volume) <(expansion) In the case of (suction volume / compression suction volume), a refrigeration cycle apparatus is disclosed in which pressure is reduced and pre-expanded by a predetermined pressure before the expansion inlet (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-150750 (

pages

5 and 6, FIG. 3 etc.)

In the refrigeration cycle apparatus described in Patent Document 1, matching is performed under operating conditions that deviate from the restriction of a constant density ratio. Therefore, a bypass circuit provided with a control valve (control valve 7) in parallel with the expander (expander 6) is provided. O. P. The opening degree of the control valve is adjusted based on the bypass amount ratio determined by determining the maximum optimum high pressure.

However, in the refrigeration cycle apparatus described in Patent Document 1, in order to obtain flow rate matching when (expansion inlet refrigerant specific volume / compression inlet refrigerant specific volume) <(expansion suction volume / compression suction volume). Pre-expansion is often performed in the liquid phase or the supercritical region on the liquid phase side, and the specific volume change is small for the reduced pressure width. For this reason, most of the difference between the high and low pressures is pre-expanded, or it is pre-expanded until recovery power cannot be obtained, and there is a possibility that matching cannot be achieved.

In the refrigeration cycle apparatus described in Patent Document 1, C.I. O. P. Although the bypass amount is determined so as to maximize the refrigerant flow rate, the refrigerant flow rate to be bypassed is enthalpy-expanded by the expansion device (control valve 7). Therefore, the amount of energy cannot be recovered, and the expansion energy is lost as compared with the case where the energy is not bypassed.

The present invention has been made to solve the above-described problems. A refrigeration cycle apparatus that enables flow rate matching without performing pre-expansion or expansion mechanism bypass, and an expander mounted on the refrigeration cycle apparatus. It is intended to provide.

A refrigeration cycle apparatus according to the present invention includes a main compressor, a radiator that cools a high-pressure refrigerant, an expansion mechanism that recovers expansion power when the refrigerant is decompressed, and a sub-compression mechanism that compresses the refrigerant using the expansion power. An expansion machine, an evaporator for heating the low-pressure refrigerant, and an additional compression mechanism for further boosting the refrigerant compressed by the sub-compression mechanism, wherein the sub-compression mechanism is disposed downstream of the evaporator, and the expansion The mechanism is a refrigeration cycle apparatus disposed downstream of the radiator and upstream of the evaporator, wherein the expander has spirals on both sides of the base plate and sucked into the expansion mechanism A high-pressure introduction hole that guides the pressure of the refrigerant to the sub-compression mechanism side is disposed opposite to the swing scroll formed in the base plate, and constitutes the expansion mechanism together with the swing scroll Expansion side A fixed scroll; and a sub-compression side fixed scroll that is disposed opposite to the expansion-side fixed scroll of the swing scroll and that constitutes the sub-compression mechanism together with the swing scroll. It is characterized by.

An expander according to the present invention is an expander having an expansion mechanism that recovers expansion power during decompression of a refrigerant and a sub-compression mechanism that compresses the refrigerant using the expansion power. An orbiting scroll having a spiral and having a high-pressure introduction hole formed to guide the pressure of the refrigerant sucked into the expansion mechanism to the sub-compression mechanism side, and disposed opposite to the orbiting scroll, the orbiting scroll And an expansion side fixed scroll that constitutes the expansion mechanism, and a sub compression side fixed that is disposed opposite to the expansion side fixed scroll of the swing scroll and that forms the sub compression mechanism together with the swing scroll An eccentric seal provided at a sliding portion of the scroll, the swing scroll and the sub-compression side fixed scroll, and disposed on the shaft side of the eccentric seal, and the swing scroll And a concentric seal provided at a sliding portion between the sub-compression side fixed scroll and the high pressure introduction hole is opened between the concentric seal and the eccentric seal. To do.

According to the refrigeration cycle apparatus according to the present invention, flow rate matching is possible without performing pre-expansion or expansion mechanism bypass, which is more efficient than when performing flow rate matching by bypass / pre-expansion, or flow rate matching is not possible with pre-expansion. Flow rate matching is possible even under different conditions, and the operating range is wide.

According to the expander according to the present invention, it is possible to reduce heat leakage via the base plate at the center of the orbiting scroll by forming the high pressure introduction hole, and to introduce the pre-expansion pressure to the sub-compression vortex side. As a result, the balance of the axial gas load acting on the orbiting scroll can be improved, and the operational stability is improved.

It is a circuit block diagram which represents typically the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a Mollier diagram which shows the operation | movement condition of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the schematic cross-sectional structure of the expander mounted in the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. It is a top view which shows the state which looked at the rocking scroll of the expander mounted in the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention from the sub compression vortex side. It is a top view which shows the state which looked at the swing scroll of the expander mounted in the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention from the expansion spiral side. It is a fragmentary sectional view which shows typically the condition of the thrust which acts on the rocking | fluctuation scroll of the expander mounted in the refrigerating cycle apparatus which concerns on Embodiment 1 of this invention. It is a table | surface which shows four typical operating conditions of a refrigerating-cycle apparatus. It is a circuit block diagram which represents typically the refrigerant circuit structure of the conventional refrigeration cycle apparatus. It is a table | surface which shows the cycle calculation result at the time of carrying out flow volume matching by the conventional system. 6 is a table showing a cycle calculation result when flow matching is performed in a branch flow in the refrigeration cycle apparatus according to Embodiment 1. It is a circuit block diagram which represents typically the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention. It is a circuit block diagram which represents typically the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a circuit configuration diagram schematically showing a refrigerant circuit configuration of a refrigeration cycle apparatus 100 according to Embodiment 1 of the present invention. The circuit configuration and operation of the refrigeration cycle apparatus 100 will be described with reference to FIG. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one. Further, in the following drawings including FIG. 1, the same reference numerals denote the same or equivalent parts, and this is common throughout the entire specification. Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

The refrigeration cycle apparatus 100 according to Embodiment 1 is used as an apparatus having a refrigeration cycle for circulating a refrigerant, such as a refrigerator, a freezer, a vending machine, an air conditioner, a refrigeration apparatus, a water heater, or the like. The refrigeration cycle apparatus 100 includes a main compressor 5, a radiator 11, a pre-expansion valve 14, an expander 1, an evaporator 12, a second compressor 23, and a check valve 81. Yes. The main compressor 5, the radiator 11, the pre-expansion valve 14, the expansion mechanism 2 of the expander 1, and the evaporator 12 are connected in series, and the sub-compression mechanism 3 of the expander 1, the check valve 81 and the second compressor 23 are connected in series.

That is, in the refrigeration cycle apparatus 100, the main compression mechanism 7 of the main compressor 5 and the sub compression mechanism 3 of the expander 1 are arranged in parallel on the outlet side of the evaporator 12. The discharge side of the sub-compression mechanism 3 of the expander 1 is connected to the suction side of the second compression mechanism 25 of the second compressor 23 via a check valve 81. The discharge side of the second compression mechanism 25 of the second compressor 23 and the discharge side of the main compression mechanism 7 of the main compressor 5 are connected before the inlet of the radiator 11. The outlet side of the radiator 11 is connected to the inlet side of the expansion mechanism 2 of the expander 1 via the pre-expansion valve 14. The outlet side of the expansion mechanism 2 of the expander 1 is connected to the inlet side of the evaporator 12.

The main compressor 5 has a motor 6 and a main compression mechanism 7 driven by the motor 6, sucks the refrigerant flowing out of the evaporator 12, and compresses the refrigerant to bring it into a high temperature / high pressure state. . The main compressor 5 may be composed of, for example, an inverter compressor capable of capacity control. The radiator 11 functions as a condenser or a gas cooler according to the refrigerant used, and performs heat exchange between air supplied from a blower (not shown) and the refrigerant. The pre-expansion valve 14 expands the refrigerant by depressurizing it, and it is preferable that the pre-expansion valve 14 is constituted by a valve whose opening degree can be variably controlled, for example, an electronic expansion valve. The evaporator 12 performs heat exchange between air supplied from a blower (not shown) and the refrigerant.

The expander 1 is an integrated scroll-type expansion mechanism 2 and sub-compression mechanism 3. The expansion mechanism 2 collects expansion power generated when the refrigerant expands, and the expansion power collected by the sub-compression mechanism 3 is recovered. It has the function of compressing the refrigerant using it. The second compressor 23 has a motor 24 and a second compression mechanism 25 driven by the motor 24, sucks the refrigerant discharged from the sub-compression mechanism 3 of the expander 1, and keeps the refrigerant in a high temperature / high pressure state. It is to make. That is, the second compressor 23 has a function as an additional compression mechanism. The check valve 81 is installed between the sub-compression mechanism 3 of the expander 1 and the second compressor 23 and allows the refrigerant to flow only in one side.

Here, the operation of the refrigeration cycle apparatus 100 will be described.
When electricity is supplied to the motor 6 of the main compressor 5, the main compression mechanism 7 is driven. In the main compression mechanism 7, the sucked refrigerant is increased in pressure from the low pressure Pl to the high pressure Ph and is discharged. The high-temperature and high-pressure refrigerant discharged from the main compressor 5 is cooled by releasing heat from the radiator 11. The refrigerant cooled by the radiator 11 flows into the expansion mechanism 2 of the expander 1. In the expander 1, power generated when the refrigerant flowing into the expansion mechanism 2 is decompressed is recovered by the expansion mechanism 2, and the sub-compression mechanism 3 is driven by the recovered expansion power.

By operating the sub-compression mechanism 3 of the expander 1, the refrigerant circulating in the refrigeration cycle is divided into w: (1-w) by the sub-compression mechanism 3 of the expander 1 and the main compression mechanism 7 of the main compressor 5. The At this time, if the refrigerant specific volume at the inlet of the expansion mechanism 2 is vexi, the refrigerant specific volume at the inlet of the sub-compression mechanism 3 is vs, and the expansion mechanism suction volume / sub-compression mechanism suction volume is σvEC ^* , w is 1 / σvEC ^*. By adjusting the amount of suction (rotational speed) of the main compressor 5 so as to be x (vexi / vs), the flow rate between expansion / sub-compression can be matched.

Further, the sub-compression mechanism 3 compresses the refrigerant corresponding to the split flow ratio w from Pl to an intermediate pressure Pm corresponding to the recovered power, and the second compression mechanism 25 driven by the motor 24 performs additional compression from Pm to Ph. By covering this, the power between expansion / sub-compression can be balanced. That is, while the suction volume ratio σvEC ^* of the expander 1 is fixed and the recovered power is determined depending on the conditions, the flow rate matching with the main compressor 5 is performed by matching the flow rate with the main compressor 5. The additional compression compresses the power shift and matches.

In FIG. 1, a pre-expansion valve 14 is described. This is for controlling the pressure on the expansion mechanism side during a transition such as startup, and is not fully involved in flow rate matching during normal operation. ing.

The operation state of the cycle at this time is shown on the Mollier diagram as shown in FIG. In FIG. 2, the vertical axis represents the refrigerant pressure P, and the horizontal axis represents the specific enthalpy h. Point b → point c shown in FIG. 2 represents the cooling process in the radiator 11 in FIG. 1, and CO ₂ is assumed as the refrigerant, so the pressure Ph exceeds the critical pressure.

When the pressure is reduced from the outlet of the radiator 11 with a throttling device that does not recover power, such as an expansion valve, the pressure is reduced at a constant enthalpy at a constant enthalpy from point c to point d ′. When the pressure is reduced while generating expansion power, the process from point c to point d is followed. This specific enthalpy difference d'-d at the time of pressure reduction corresponds to the energy recovered as power, and is used as power when the flow rate w is compressed by the sub-compression mechanism 3 from point a to point e. The additional compression performed by the second compressor 23 is represented by a point e → a point b, and the compression in the main compressor 5 is represented by a point a → a point b.

At this time, (enthalpy difference ha−hd) × (flow rate 1) equivalent is refrigeration capacity, and (enthalpy difference he−ha) × (flow rate 1−w) + (enthalpy difference hb−he) × (flow rate 1) equivalent Is consumed by the motor 6 of the main compressor 5 and the motor 24 of the second compressor 23, so this ratio is the so-called cycle C.I. O. P. It becomes. Compared with cycle point a → point b → point c → point d ′ → point a when power recovery is not performed, the input (enthalpy difference he−ha) × (flow rate w) and the refrigeration capacity (enthalpy difference hd) '-Hd) × (flow rate 1) is C.I. O. P. It contributes to improvement.

As described above, the diversion ratio w is determined according to the suction volume ratio σvEC ^* of the expander 1, and the ratio (hc−hd) / (he−ha) of the enthalpy difference between the expansion mechanism 2 side and the sub compression mechanism 3 side is , W are equal, and the level of Pm also depends on σvEC ^* . In the expander 1, since the refrigerant on the expansion mechanism 2 side and the sub compression mechanism 3 side flows into the same container and exchanges power due to gas pressure, the load between the expansion mechanism 2 and the sub compression mechanism 3; In consideration of heat transfer, it is possible to adjust the pressure and temperature of the sub-compression discharge corresponding to the point e by setting σvEC ^* .

FIG. 3 is a longitudinal sectional view showing a schematic sectional configuration of the expander 1 mounted in the refrigeration cycle apparatus 100 according to the first embodiment. Based on FIG. 3, the structure of the expander 1 is demonstrated. As described above, the expander 1 includes the scroll-type expansion mechanism 2 and the sub-compression mechanism 3, and the expansion power generated when the refrigerant is expanded is recovered by the expansion mechanism 2, and the recovered expansion power is recovered. It has a function of compressing the refrigerant by the sub-compression mechanism 3. The expansion mechanism 2 and the sub-compression mechanism 3 are accommodated inside a sealed container 4 that is a pressure container. As shown in FIG. 3, the expansion mechanism 2 is disposed below the sealed container 4, and the sub-compression mechanism 3 is disposed above the expansion mechanism 2.

The lubricating oil 9 such as refrigerating machine oil is stored at the bottom of the sealed container 4. In the sealed container 4, an expansion suction pipe 15 that causes the expansion mechanism 2 to suck the refrigerant, an expansion discharge pipe 16 that discharges the refrigerant expanded by the expansion mechanism 2, and a sub compression suction pipe 19 that causes the sub compression mechanism 3 to suck the refrigerant. And a sub-compression discharge pipe 20 for discharging the refrigerant compressed by the sub-compression mechanism 3 is connected. The expansion suction pipe 15, the sub compression discharge pipe 20, and the expansion discharge pipe 16 are provided so as to communicate with the inside from the side surface of the sealed container 4. The sub-compression suction pipe 19 is provided so as to communicate with the inside from the upper surface of the sealed container 4.

The expansion mechanism 2 decompresses and expands the refrigerant sucked from the expansion suction pipe 15 and discharges the refrigerant from the expansion discharge pipe 16. The expansion mechanism 2 includes an expansion side fixed scroll 51 in which an expansion side spiral 51a is formed on a base plate, and an orbiting scroll 52 in which an expansion side spiral 52a is formed on the base plate. As shown in FIG. 3, the expansion side fixed scroll 51 is disposed on the lower side, and the swing scroll 52 is disposed on the upper side. The expansion side spiral 51 a is erected as a spiral protrusion on one surface of the base plate of the expansion side fixed scroll 51. The expansion-side spiral 52 a is erected as a spiral protrusion on one surface of the base plate of the swing scroll 52.

The expansion-side spiral 51a of the expansion-side fixed scroll 51 and the expansion-side spiral 52a of the swing scroll 52 are arranged so as to mesh with each other. An expansion chamber 51d whose volume changes is formed by the relative swinging motion of the expansion side spiral 51a and the expansion side spiral 52a. An eccentric seal 72b is provided on the end surface of the swing scroll 52 on the side of the expansion side fixed scroll 51 so as to surround the shaft 78.

The sub-compression mechanism 3 compresses the refrigerant sucked from the sub-compression suction pipe 19 and discharges it from the sub-compression discharge pipe 20. The sub-compression mechanism 3 has a sub-compression side fixed scroll 61 in which a sub-compression side spiral 61a is formed on a base plate, and an orbiting scroll 52 in which a sub-compression side spiral 62a is formed on a base plate. ing. As shown in FIG. 3, the sub-compression side fixed scroll 61 is disposed on the upper side, and the swing scroll 52 is disposed on the lower side. The sub-compression side spiral 61 a is erected as a spiral projection on one surface of the base plate of the sub-compression side fixed scroll 61. The sub-compression side spiral 62 a is erected as a spiral protrusion on one surface of the base plate of the swing scroll 52.

The sub-compression side spiral 61a of the sub-compression side fixed scroll 61 and the sub-compression side spiral 62a of the orbiting scroll 52 are arranged so as to mesh with each other. A sub-compression chamber 61d in which the volume changes is formed by relatively swinging the sub-compression side spiral 61a and the sub-compression side spiral 62a. In addition, oil return holes 31 for returning the lubricating oil 9 to the bottom of the hermetic container 4 are formed through the outer peripheral portions of the sub-compression side fixed scroll 61 and the expansion side fixed scroll 51 in the axial direction. Further, an eccentric seal 72 a and a concentric seal 73 are provided on the end surface of the swing scroll 52 on the side of the sub-compression side fixed scroll 61 so as to surround the shaft 78. Further, a discharge valve 32 is provided at the refrigerant discharge portion of the sub-compression side fixed scroll 61. The discharge valve 32 is opened and closed to communicate / block the sub compression chamber 61d and the sub compression discharge pipe 20.

Through holes are formed in substantially the center portions of the expansion side fixed scroll 51, the swing scroll 52, and the sub compression side fixed scroll 61, and a shaft 78 is fitted into these through holes. The orbiting scroll 52 of the expansion mechanism 2 and the orbiting scroll 52 of the sub-compression mechanism 3 are integrally configured so as to share a base plate, and a high-pressure introduction hole 52e is formed to penetrate in the axial direction. The high-pressure introduction hole 52e communicates the expansion chamber 51d and the space between the eccentric seal 72a and the concentric seal 73.

The shaft 78 is rotatably supported at both ends by a lower bearing 51b and an upper bearing 61b formed at the center of each of the expansion side fixed scroll 51 and the sub compression side fixed scroll 61. In the swing scroll 52, a swing bearing 52b provided in a thick portion formed at the center of each of the expansion side spiral 52a and the sub compression side spiral 61a is penetrated and supported by a crank portion 78a formed on a shaft 78. As the shaft 78 rotates, it can swing.

An oil pump 76 that pumps up the lubricating oil 9 is attached to the lower end of the shaft 78. Further, an oil supply hole (not shown) through which the lubricating oil 9 pumped up by the oil pump 76 is conducted is formed in the shaft 78. The lubricating oil 9 pumped up by the oil pump 76 is supplied to the lower bearing 51b and the upper bearing 61b through an oil supply hole formed in the shaft 78. The lubricating oil 9 used in each bearing returns to the bottom of the sealed container 4 through the oil return hole 31. A rocking scroll motion space having a predetermined size is formed on the outer peripheral side of the rocking scroll 52 so that the rocking scroll 52 can be swung.

An Oldham groove 52d is formed on the outer peripheral side of the orbiting scroll 52 and on the side of the expansion side fixed scroll 51. The Oldham groove 52d restricts the rotation motion of the orbiting scroll 52 and enables the revolving motion. For this purpose, an Oldham ring 77 is arranged. A balancer 79a is provided on the upper end side of the shaft 78, and a balancer 79b is provided on the lower end side. The balancer 79a and the balancer 79b are for canceling the centrifugal force generated by the swinging motion of the swing scroll 52, and the material, size, shape and the like are not particularly limited.

That is, as shown in FIG. 3, the expander 1 includes an orbiting scroll 52 in which an expansion-side spiral 52 a and a sub-compression side spiral 62 a are formed on both sides of a base plate so as to face each other. The expansion mechanism 2 and the sub compression mechanism 3 are configured in combination with the sub compression side fixed scroll 61.

Therefore, in the expander 1, the swing scroll 52 is regulated by the Oldham ring 77 and the shaft 78 and swings with the power when the high-pressure refrigerant flowing from the expansion suction pipe 15 expands in the expansion mechanism 2. The sub-compression mechanism 3 boosts the low-pressure refrigerant sucked from the sub-compression suction pipe 19 through a suction port (not shown for another phase cross section). Then, the refrigerant whose pressure has been increased to the intermediate pressure pushes the discharge valve 32 open from the discharge port (different cross section) and is discharged to the sub-compression discharge pipe 20. The expanded refrigerant is discharged from the expansion discharge pipe 16 (different cross section).

When using an expander having a double-sided scroll mechanism in which the expansion side spiral 52a and the sub compression side spiral 62a are integrated back to back as in the expander 1, the expansion side and the sub compression side are sandwiched by the base plate of the swing scroll. The refrigerant will pass nearby. For this reason, if the temperature difference between the expansion side and the sub-compression side is too large, there is a possibility that the heat leak through the base plate of the orbiting scroll cannot be ignored. In particular, the heat leak from the sub-compression side to the expansion side acts in the direction of reducing the cycle efficiency, so it is desirable to avoid it as much as possible.

In the Mollier diagram shown in FIG. 2, the expansion process is from point c to point d, and the sub-compression process is from point a to point e, so point c is at the center of the expansion side spiral, and The refrigerant in the state of point d, the point a at the sub-compression side spiral outer periphery, and the point e at the center of the sub-compression side spiral is in contact. That is, the refrigerant in the state of points e and c at the center of the base plate and the refrigerant at points a and d at the outer periphery of the base plate are adjacent to each other back to back. Among these points, the points c, d, and a are determined from the operating conditions, but the level of Pm depends on the expansion / sub-compression suction volume ratio σvEC ^* as described above. The state quantity can be adjusted by changing the diversion ratio w depending on how σvEC ^* is selected at the time of design.

Further, since the expansion process of high pressure Ph to low pressure Pl and the sub-compression process of low pressure Pl to intermediate pressure Pm proceed on both sides of the orbiting scroll, the axial gas load (thrust) acting on the orbiting scroll is not equal. If the thrust difference becomes excessive depending on the intermediate pressure Pm, an increase in sliding loss or a decrease in operational stability due to the spiral tip pressing will be caused. Therefore, the suction volume ratio σvEC ^* must be selected in consideration of both heat leak and thrust. However, the temperature difference between the points e to c at the center of the base plate under the predetermined condition is the internal heat leak. When the suction volume ratio of the expander 1 is selected so that the reduction in cycle efficiency due to the pressure is acceptable, Pm is approximately (Ph + Pl) / 2 or less.

In this situation, although it depends on the shape and dimensions of the spiral, it is inevitable that excessive thrust will occur at the sub-compression side spiral tip due to the thrust difference. However, it is possible to increase the thrust acting on the sub-compression side and to balance it with the thrust from the expansion side by introducing the high pressure on the expansion suction side to the central portion on the sub-compression side. Therefore, in the expander 1, by providing the high pressure introduction hole 52e penetrating the orbiting scroll in the axial direction, the pre-expansion high pressure on the expansion inlet side is transferred between the concentric seal 73 and the eccentric seal 72a on the subcompression side central end face. It is made to act on the part.

FIG. 4 is a plan view showing a state in which the orbiting scroll is viewed from the sub compression spiral side. FIG. 5 is a plan view showing a state in which the swing scroll is viewed from the expansion spiral side. Based on FIG.4 and FIG.5, the characteristic of the expander 1 is demonstrated in more detail. The orbiting scroll is formed with an orbiting bearing 52b through which the shaft 78 penetrates at the center, and the periphery of the orbiting bearing 52b is a so-called bulbous shape (between the involute winding start point) on both the expansion side and the sub compression side. Are formed by connecting them with arcs).

The orbiting scroll of the expander 1 is formed by dimensionally reducing the expansion side spiral 52a that operates between the low pressure Pl and the high pressure Ph compared to the sub compression side spiral 62a that operates between the low pressure Pl and the intermediate pressure Pm. The pressure receiving area of the thrust acting from the expansion side is suppressed. Further, an Oldham groove 52d into which the key part of the Oldham ring 77 is fitted is formed on the outer peripheral portion on the expansion side of the expander 1, and the Oldham groove is formed on the expansion side outer peripheral portion of the swing scroll base plate as shown in FIG. The posture of the ring 77 is adjusted between the ring 77 and the expansion side fixed scroll 51.

An eccentric seal 72b separates the swing bearing 52b communicating with the low pressure of the atmosphere in the container and the central portion of the pre-expansion high pressure on the end surface of the bulb-shaped portion outside the swing bearing 52b of the expansion side spiral 52a shown in FIG. A high-pressure introduction hole 52e is formed in the innermost peripheral portion where the expansion chamber 51d is formed so as to guide the pressure immediately after expansion and suction to the sub-compression side. The high-pressure introduction hole 52e on the sub-compression side shown in FIG. 4 is opened between the concentric seal 73 and the eccentric seal 72a on the bulb-shaped end surface, and the concentric seal 73 is intermediate between the low-pressure rocking bearing portion. Since the eccentric seal 72a is separated from the sub-compression central portion of the pressure, a high pressure is applied to the inner portion of the eccentric seal 72a and the outer portion of the concentric seal 73.

FIG. 6 is a partial sectional view schematically showing the state of thrust acting on the orbiting scroll. Based on FIG. 6, the thrust which acts on the swing scroll of the expander 1 is demonstrated in detail. Note that the arrows shown in FIG. 6 represent the thrust loads acting on both sides of the orbiting scroll.

6, high pressure Ph to low pressure Pl act on the spiral portion outside the expansion side eccentric seal 72b, and intermediate pressure Pm to low pressure Pl act on the spiral portion outside the sub compression side eccentric seal 72a. Further, the high pressure Ph guided from the expansion side by the high pressure introduction hole 52e acts on the inner side of the eccentric seal 72a and the outer side of the concentric seal 73, so that the thrust on the expansion side and the sub-compression side are almost balanced in total. It has become. At this time, providing a communication path (high-pressure introduction hole 52e) between the expansion side and the sub compression side increases heat leakage when the temperature difference between the expansion side central portion and the sub compression side central portion is large. There is no problem as long as the temperature difference is suppressed by selecting the suction volume ratio.

Further, the high-pressure introduction hole 52e that guides the high pressure before expansion to the end face of the bulb-shaped portion of the sub-compression side spiral is represented as a fine hole that penetrates the orbiting scroll as shown in the cross-sectional view of FIG. Even if it is guided from, for example, the conduit before the expansion suction pipe 15 before being sucked to the end face of the sub compression side spiral central bulb shape portion through the sub compression side fixed scroll 61, for example, there is no functional change. In this case, the high-pressure introduction hole 52e opened at the tooth bottom surface of the center portion of the sub-compression fixed scroll is always inside the eccentric seal 72a even if the swinging scroll swings outside the concentric seal 73 of the counterpart swing scroll. Needless to say, it must be opened at such a position.

FIG. 7 is a table showing four typical operating conditions of the refrigeration cycle apparatus. FIG. 8 is a circuit configuration diagram schematically showing a refrigerant circuit configuration of a conventional refrigeration cycle apparatus (hereinafter referred to as refrigeration cycle apparatus 100 ′). FIG. 9 is a table showing the cycle calculation results when the flow rate matching is performed by the conventional method. Based on FIGS. 7 to 9, four typical operating conditions in the refrigeration cycle apparatus 100 'will be described. The refrigeration cycle apparatus 100 ′ shown in FIG. 8 includes a refrigeration cycle that performs flow rate matching by pre-expansion (expansion valve 13 ′) / expansion mechanism bypass (bypass pipe 40 ′).

The refrigeration cycle apparatus 100 ′ is different from the refrigeration cycle apparatus 100 according to the first embodiment in that the second compressor 23 is not provided and the expansion valve 13 ′ and the bypass pipe 40 ′ are provided. Yes. When the flow rate matching is performed in the refrigeration cycle apparatus 100 ′ shown in FIG. 8 for the four conditions shown in FIG. 7, the pre-expansion rate y, which is the ratio of the bypass ratio x to the total high-low pressure difference of the decompression width pre-expanded before the expansion inlet. Are both 0 (expansion suction volume / compression suction volume), that is, determined by operating conditions (expansion inlet refrigerant specific volume / compression inlet refrigerant specific volume) is σvEC. Further, (expansion inlet refrigerant specific volume / expansion outlet refrigerant specific volume) is σvE. Cycle C. at this time O. P. Is C.I. O. P. th.

ΣvE on the operating condition side corresponds to the expansion volume ratio (expansion start volume / expansion completion volume) = σvE ^* of the expansion mechanism 2 ′, but σvE ^* is usually unique to the expander design and cannot be changed ^. When the difference between σvE and σvE becomes large, the reduction in recovered power due to underexpansion and overexpansion becomes significant.

For a certain condition, (expansion suction volume / compression suction volume) = σvEC ^* and (expansion inlet refrigerant specific volume / expansion outlet refrigerant specific volume) which are equal to (expansion inlet refrigerant specific volume / compression inlet refrigerant specific volume) (Expansion start volume / expansion completion volume) = σvE ^*, and the flow rate matching with the pre-expansion rate y and the bypass ratio x for the remaining three conditions is shown in FIG. 9 shows.

In FIG. 9, with respect to the condition that (expansion inlet refrigerant specific volume / compression inlet refrigerant specific volume) is σvEC and (expansion inlet refrigerant specific volume / expansion outlet refrigerant specific volume) is σvE, the expansion volume ratio = (expansion suction volume / When using the expander 1 ′ having a compression suction volume (σvEC ^* ) and (expansion start volume / expansion completion volume) σvE ^* , the pre-expansion ratio y, bypass ratio x, and sub-compression outlet pressure necessary for flow rate matching are used. Intermediate pressure Pm and C. O. P. C. shown in FIG. O. P. The ratio to th is shown.

When σvEC ^* = σvEC, neither bypass nor pre-expansion is required. When σvEC ^* <σvEC, bypass flow is performed, and when σvEC ^* > σvEC, pre-expansion is performed to match the flow rate. However, if σvEC ^* is too larger than σvEC, matching can be achieved even if the maximum pre-expansion occurs C. O. P. A situation occurs in which the ratio is less than 100% and the performance improvement effect by the recovery of the expansion power cannot be obtained. This is the cooling rated condition when σvEC ^* is matched to the heating condition, and if the expander 1 ′ designed for heating is used under the cooling rated condition, it is easily understood that this method is not suitable. it can.

On the other hand, the cycle calculation result in the case where the flow rate matching is performed with the diversion ratio w in the refrigeration cycle apparatus 100 according to Embodiment 1 is as shown in FIG. Here, when σvEC ^* is fixed to 0.5, w required for matching, intermediate pressure Pm depending on w, and C.I. O. P. The ratio is shown. Since there is no power recovery loss associated with flow rate matching, it is insufficient when σvE does not match the expansion volume ratio σvE ^* , especially when cooling operation is designed for heating conditions, and when heating operation is designed for cooling conditions. The effect of expansion or overexpansion is C.I. O. P. As shown in FIG. O. P. It can be seen that the ratio never falls below 100%.

The operating state of the refrigeration cycle apparatus 100 'can be diverted from the Mollier diagram of FIG. After sub-compression of point a → point e by the sub-compression mechanism 3 ′, compression of the point e → point b is performed by the main compressor 5 ′, and the refrigerant after cooling of the point b → point c by the radiator 11 ′ is In the expansion mechanism 2 ', the isentropic expansion process from point c to point d is followed. However, if the flow rate matching is necessary, the flow rate x is bypassed and decompressed by the expansion valve 13 ', so that an isoenthalpy expansion process from point c to point d' follows and the flow rate passing through the expansion mechanism 2 'is increased. 1-x, or isentropic expansion from the point c by the preexpansion valve 14 toward the point d ′ by the preexpansion rate y, followed by isentropic expansion by the expansion mechanism 2 ′.

Therefore, the recovery power is the enthalpy difference due to the isentropic expansion of the pressure Pl + (Ph−Pl) · (1−y) to Pl in the flow rate 1−x minutes of the enthalpy difference d′−d in the case of bypass and in the case of preexpansion. In any case, the amount is reduced as compared with the case where the entire amount is entropy expanded without bypassing or pre-expanding. There is almost no reduction in the recovery power associated with the flow rate matching, and the refrigeration cycle apparatus 100 ′ has a recovery power that is less than the loss associated with the flow rate matching, compared with the refrigeration cycle apparatus 100 that increases the pressure by the branch flow ratio w by the sub-compression mechanism 3 ′. Since the total flow rate is increased, the level of Pm is lower than that in FIG. 2, and so is the value of Pm in the tables of FIGS.

In the conventional matching method, the ratio of the volume flow rate at the expansion / sub-compression inlet is matched to the ratio of the suction volume of the expansion / sub-compression by bypassing or pre-expanding the expansion mechanism, that is, the volume flow rate is adjusted mainly on the expansion process side. In order to do so, the recovery power was reduced, and the boosting work in the main compressor was to be increased accordingly. On the other hand, in the matching method of the refrigeration cycle apparatus 100, whether the compression process from the low pressure Pl to the intermediate pressure Pm is performed by the sub-compression mechanism 3 of the expander 1 or the main compression mechanism 7 driven by a power source. The flow rate is adjusted on the side of the compression process side, that is, the compression process side. This is the C. of the matching method by the refrigeration cycle apparatus 100 ′ and the matching method by the split flow of the refrigeration cycle apparatus 100. O. P. It is a factor of the difference.

As described above, according to the refrigeration cycle apparatus 100 according to Embodiment 1, the ratio w of the flow rate sucked into the sub compression mechanism 3 with respect to the total flow rate is (expansion inlet refrigerant specific volume / sub compression inlet refrigerant specific volume). / (Expansion suction volume / Sub-compression suction volume) By adjusting the flow rate sucked into the main compressor side, the flow rate matching becomes possible, and the efficiency is higher than the flow rate matching by bypass / pre-expansion Alternatively, flow rate matching is possible even under conditions where flow rate matching was not possible with pre-expansion, and the operating range is wide.

Further, according to the expander 1 used in the refrigeration cycle apparatus 100, the temperature difference between the sub-compression discharge side and the expansion inlet side is suppressed by adjusting the (expansion suction volume / sub-compression suction volume) ratio. Heat leakage via the base plate in the center of the scroll can be reduced, and the balance of the axial gas load acting on the orbiting scroll can be improved by introducing the pre-expansion pressure to the sub-compression vortex side, resulting in operational stability Becomes better. Therefore, the refrigeration cycle apparatus 100 equipped with the expander 1 has a small reduction in cycle efficiency due to internal heat leakage in addition to the above effects.

In FIG. 2, the Mollier diagram assuming a CO ₂ refrigerant has been described as an example. However, a refrigerant other than CO ₂ can be used for the refrigeration cycle apparatus 100. The refrigerant | coolant which can be used for the refrigerating-cycle apparatus 100 is demonstrated. Examples of the refrigerant that can be used in the refrigeration cycle apparatus 100 include a non-azeotropic mixed refrigerant, a pseudo-azeotropic mixed refrigerant, and a single refrigerant. Non-azeotropic refrigerant mixture includes R407C (R32 / R125 / R134a) which is an HFC (hydrofluorocarbon) refrigerant. The pseudo azeotropic refrigerant mixture includes R410A (R32 / R125) and R404A (R125 / R143a / R134a) which are HFC refrigerants.

Also, the single refrigerant includes R22 which is an HCFC (hydrochlorofluorocarbon) refrigerant, R134a which is an HFC refrigerant, and the like. In addition, propane, isobutane, ammonia or the like, which is a natural refrigerant, can also be used. Further, examples of the refrigerant that becomes a supercritical state include a mixed refrigerant of carbon dioxide and ether (for example, dimethyl ether, hydrofluoroether, etc.). Therefore, it is good to use the refrigerant | coolant according to the use and the objective of the refrigerating cycle apparatus 100. FIG.

Embodiment 2.
FIG. 11 is a circuit configuration diagram schematically showing the refrigerant circuit configuration of the refrigeration cycle apparatus 100a according to Embodiment 2 of the present invention. Based on FIG. 11, the characteristic point of the refrigerating cycle apparatus 100a is demonstrated. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and differences from the first embodiment will be mainly described. The refrigeration cycle apparatus 100a can also use the various refrigerants described in the first embodiment.

The refrigeration cycle apparatus 100a according to Embodiment 2 is also equipped with a refrigeration cycle that circulates refrigerant, such as a refrigerator, a freezer, a vending machine, an air conditioner, like the refrigeration cycle apparatus 100 according to Embodiment 1. Used as refrigeration equipment, water heater, etc. The refrigeration cycle apparatus 100a also has a main compressor 5, a radiator 11, a pre-expansion valve 14, an expander 1, an evaporator 12, a second compressor 23, and a check valve 81. Yes. However, the connection state of each component device is different from that of the refrigeration cycle apparatus 100 according to Embodiment 1.

In the refrigeration cycle apparatus 100a, the refrigerant 12 is diverted to the sub-compression mechanism 3 at the outlet of the evaporator 12 and the refrigerant flow rate 1-w is diverted to the main compressor 5, but the second compressor 23 only discharges the sub-compression mechanism 3 discharge. Rather than performing additional compression, the amount of discharge from the main compressor 5 is also sucked and increased from an intermediate pressure to a high pressure. That is, in the refrigeration cycle apparatus 100 according to Embodiment 1, the main compressor 5 and the second compressor 23 are arranged in parallel, but in the refrigeration cycle apparatus 100a, the main compressor 5 and the second compressor 23 are in series. The refrigerant discharged from the sub compression mechanism 3 is guided between the main compressor 5 and the second compressor 23 via the check valve 81.

Since the second compressor 23 of the refrigeration cycle apparatus 100 according to Embodiment 1 additionally compresses only the sub-compressed refrigerant, a compressor having a small stroke volume can be used. On the other hand, the second compressor 23 of the refrigeration cycle apparatus 100a according to the second embodiment compresses not only the sub-compressed refrigerant but also the refrigerant after being compressed by the main compressor 5. A relatively large stroke volume can be used.

For example, the stroke volume when the number of rotations at the design point of each compressor (the main compressor 5 and the second compressor 23) of the refrigeration cycle apparatus 100 according to Embodiment 1 is about 50 [rps] is as follows. The main compressor 5 is about 29.2 [cc / rev], and the second compressor 23 is about 5.9 [cc / rev]. On the other hand, the stroke volume when the number of revolutions at the design point of each compressor (the main compressor 5 and the second compressor 23) of the refrigeration cycle apparatus 100a according to Embodiment 2 is about 50 [rps]. The main compressor 5 is about 29.2 [cc / rev], and the second compressor 23 is about 26.9 [cc / rev].

When using a positive displacement compressor, it is generally difficult to maintain efficiency as the compressor has a smaller stroke volume. Therefore, in the refrigeration cycle apparatus 100a, a compressor having a relatively large stroke volume can be used for the second compressor 23, so that the efficiency of the entire cycle is improved.

As described above, according to the refrigeration cycle apparatus 100a according to Embodiment 2, the ratio w of the flow rate sucked into the sub compression mechanism 3 with respect to the total flow rate is (expansion inlet refrigerant specific volume / sub compression inlet refrigerant specific volume). / (Expansion suction volume / Sub-compression suction volume) By adjusting the flow rate sucked into the main compressor side, the flow rate matching becomes possible, and the efficiency is higher than the flow rate matching by bypass / pre-expansion Alternatively, flow rate matching is possible even under conditions where flow rate matching was not possible with pre-expansion, and the operating range is wide. In addition, since a compressor having a relatively large stroke volume can be used as the second compressor 23, the efficiency of the entire cycle is further improved.

Further, according to the expander 1 used in the refrigeration cycle apparatus 100a, the temperature difference between the sub-compression discharge side and the expansion inlet side is suppressed by adjusting the (expansion suction volume / sub-compression suction volume) ratio, and swings. Heat leakage via the base plate in the center of the scroll can be reduced, and the balance of the axial gas load acting on the orbiting scroll can be improved by introducing the pre-expansion pressure to the sub-compression vortex side, resulting in operational stability Becomes better. Therefore, the refrigeration cycle apparatus 100a equipped with the expander 1 has a small reduction in cycle efficiency due to internal heat leakage in addition to the above effects.

Embodiment 3 FIG.
FIG. 12 is a circuit configuration diagram schematically showing the refrigerant circuit configuration of the refrigeration cycle apparatus 100b according to Embodiment 3 of the present invention. Based on FIG. 12, the feature point of the refrigeration cycle apparatus 100b will be described. In the third embodiment, the same reference numerals are given to the same parts as those in the first and second embodiments, and differences from the first and second embodiments will be mainly described. The refrigeration cycle apparatus 100b can also use the various refrigerants described in the first embodiment.

The refrigeration cycle apparatus 100b according to Embodiment 3 is also equipped with a refrigeration cycle that circulates the refrigerant, such as a refrigerator, a freezer, a vending machine, an air conditioner, like the refrigeration cycle apparatus 100 according to Embodiment 1. Used as refrigeration equipment, water heater, etc. The refrigeration cycle apparatus 100 b includes a main compressor 5, a radiator 11, a pre-expansion valve 14, an expander 1, an evaporator 12, and a check valve 81. That is, it is different from the refrigeration cycle apparatus 100 according to Embodiment 1 and the refrigeration cycle apparatus 100a according to Embodiment 2 in that the second compressor is not provided.

In the refrigeration cycle apparatus 100b, the refrigerant 12 is diverted to the sub-compression mechanism 3 at the outlet of the evaporator 12 and the refrigerant flow rate 1-w is diverted to the main compressor 5; Rather than performing additional compression with the two compressors, the main compressor 5 is returned to the compression chamber in the middle of compression. That is, in the refrigeration cycle apparatus 100b, intermediate pressure to high pressure increase for the total flow rate of the refrigerant is performed in the main compressor 5. Therefore, the main compressor 5 includes a path and a port (injection port) for taking in the refrigerant from the sub-compression mechanism 3 into the compression chamber.

In the refrigeration cycle apparatus 100b, although it is necessary to provide the main compressor 5 with a path and a port for taking in the refrigerant from the sub-compression mechanism 3 into the compression chamber according to the intermediate pressure, the second compressor is not provided. The cost can be reduced accordingly. That is, in the refrigeration cycle apparatus 100b, a part of the main compressor 5 plays a role of an additional compression mechanism.

As described above, according to the refrigeration cycle apparatus 100b according to Embodiment 3, the ratio w of the flow rate sucked into the sub compression mechanism 3 with respect to the total flow rate is (expansion inlet refrigerant specific volume / sub compression inlet refrigerant specific volume). / (Expansion suction volume / Sub-compression suction volume) By adjusting the flow rate sucked into the main compressor side, the flow rate matching becomes possible, and the efficiency is higher than the flow rate matching by bypass / pre-expansion Alternatively, flow rate matching is possible even under conditions where flow rate matching was not possible with pre-expansion, and the operating range is wide. In addition, since it is not necessary to provide the second compressor, it is possible to reduce the cost required for that.

Further, according to the expander 1 used in the refrigeration cycle apparatus 100b, the temperature difference between the sub-compression discharge side and the expansion inlet side is suppressed by adjusting the (expansion suction volume / sub-compression suction volume) ratio. Heat leakage via the base plate in the center of the scroll can be reduced, and the balance of the axial gas load acting on the orbiting scroll can be improved by introducing the pre-expansion pressure to the sub-compression vortex side, resulting in operational stability Becomes better. Therefore, the refrigeration cycle apparatus 100a equipped with the expander 1 has a small reduction in cycle efficiency due to internal heat leakage in addition to the above effects.

1 expander, 1 'expander, 2 expansion mechanism, 2' expansion mechanism, 3 sub compression mechanism, 3 'sub compression mechanism, 4 sealed container, 5 main compressor, 5' main compressor, 6 motor, 6 'motor 7 main compression mechanism, 7 'main compression mechanism, 9 lubricating oil, 11 radiator, 11' radiator, 12 evaporator, 12 'evaporator, 13' expansion valve, 14 pre-expansion valve, 14 'pre-expansion valve, 15 expansion suction pipe, 16 expansion discharge pipe, 19 sub compression suction pipe, 20 sub compression discharge pipe, 23 second compressor, 24 motor, 25 second compression mechanism, 31 oil return hole, 32 discharge valve, 40 'bypass pipe , 51 Expansion side fixed scroll, 51a Expansion side spiral, 51b Lower bearing, 51d Expansion chamber, 52 Swing scroll, 52a Expansion side spiral, 52b Swing bearing, 52d Oldham groove, 52 High pressure introduction hole, 61 sub compression side fixed scroll, 61a sub compression side spiral, 61b upper bearing, 61d sub compression chamber, 62a sub compression side spiral, 72a eccentric seal, 72b eccentric seal, 73 concentric seal, 76 oil pump, 77 Oldham Ring, 78 shaft, 78a crank section, 79a balancer, 79b balancer, 81 check valve, 81 ′ check valve, 100 refrigeration cycle apparatus, 100 ′ refrigeration cycle apparatus, 100a refrigeration cycle apparatus, 100b refrigeration cycle apparatus.

Claims

Main compressor, radiator that cools high-pressure refrigerant, expansion mechanism that recovers expansion power during decompression of refrigerant and sub-compression mechanism that compresses refrigerant using the expansion power, heats low-pressure refrigerant An evaporator, and an additional compression mechanism that further pressurizes the refrigerant compressed by the sub-compression mechanism, wherein the sub-compression mechanism is disposed on the downstream side of the evaporator, and the expansion mechanism is disposed on the downstream side of the radiator. A refrigeration cycle apparatus disposed upstream of the evaporator,
The expander is
An orbiting scroll having spirals on both sides of the base plate, and a high-pressure introduction hole formed in the base plate for guiding the pressure of the refrigerant sucked into the expansion mechanism to the sub-compression mechanism side;
An expansion-side fixed scroll that is disposed opposite to the swing scroll and forms the expansion mechanism together with the swing scroll;
A sub-compression side fixed scroll that is disposed opposite to the expansion-side fixed scroll of the swing scroll and that forms the sub-compression mechanism together with the swing scroll. Refrigeration cycle equipment.
The sliding portion between the swing scroll and the sub-compression side fixed scroll is provided with an eccentric seal and a concentric seal disposed on the shaft side of the eccentric seal,
The high-pressure introduction hole is
The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is opened between the concentric seal and the eccentric seal.
The additional compression mechanism is:
The refrigeration cycle apparatus according to claim 1 or 2, wherein the refrigeration cycle apparatus is a second compressor arranged in parallel with the main compressor.
The additional compression mechanism is:
The second compressor which is arranged in series with the main compressor and sucks and compresses the refrigerant compressed by the sub-compression mechanism and the refrigerant compressed by the main compressor together. The refrigeration cycle apparatus according to 1 or 2.
The additional compression mechanism is:
The refrigeration cycle apparatus according to claim 1 or 2, wherein a part of a compression mechanism of the main compressor is in charge.
The refrigeration cycle apparatus according to any one of claims 1 to 5, wherein a refrigerant that is in a supercritical state on the high pressure side is used.
An expansion mechanism having an expansion mechanism for recovering expansion power during decompression of the refrigerant and a sub-compression mechanism for compressing the refrigerant using the expansion power,
An orbiting scroll having spirals on both sides of the base plate and formed with high-pressure introduction holes for guiding the pressure of the refrigerant sucked into the expansion mechanism to the sub-compression mechanism side;
An expansion-side fixed scroll that is disposed opposite to the swing scroll and forms the expansion mechanism together with the swing scroll;
A sub-compression side fixed scroll disposed opposite to the expansion-side fixed scroll of the swing scroll and constituting the sub-compression mechanism together with the swing scroll;
An eccentric seal provided at a sliding portion between the swing scroll and the sub-compression side fixed scroll;
A concentric seal disposed on the shaft side of the eccentric seal and provided at a sliding portion between the swing scroll and the sub-compression side fixed scroll;
The high-pressure introduction hole is
An expander that is opened between the concentric seal and the eccentric seal.